With higher performance of field effect transistors (hereinafter referred to as “FETs”) which compose FET cells (unit cells) in a high frequency amplifier, the frequency of a loop oscillation of an odd mode becomes higher and the loop becomes smaller. As a result, the loop oscillation arises between the FET cells of the high frequency amplifier.
In order to restrain such a loop oscillation occurring between FET cells, a technique of arranging a resistor (inter-cell resistor) at a suitable position between FET cells or a technique of arranging a resistor (shunt resistor) between a gate of an FET and a ground terminal has been applied.
In a case of arranging a resistor between FET cells, an oscillation which occurs in a loop including adjacent FET cells may be effectively restrained, but an oscillation which occurs in a loop including non-adjacent (dispersed) FET cells may not be restrained effectively.
In a case of arranging a resistor between a gate of an FET and a ground terminal, it is necessary to provide a large inductor in order to prevent deterioration of a high frequency characteristic such as leakage of a high frequency signal.